Bought a cheap code reader off ebay, a U480 CAN/OBDII and plugged into the scoob as the eml light is on. codes found was P0031 01/02 and P0031 02/02 pending. I then erased them and cleared the eml light but after turning the ignition off and disconnecting the code reader when I tried to start the car the lights on the dash came on and I could hear the fuel pump being primed but nothing else would happen. Then the alarm sounded and went off again. I got out and returned to the car a few minutes later and it fired up without a problem but the eml came straight back on.

The code lists P0031 as HO2S Bank 1 sensor 1 Heater Circuit Low.
Does this mean heater matrix is low on coolant?

Also, looking through the I/M readout says CAT NOT RDY and O2S NOT RDY.
Does this indicate new cat and lambda needed?

Ta.

Edit; 2003 WRX blobeye

 

Its nothing to do with your heaters/coolant buddy, the heater circuit is part of the oxygen/lambda sensor. They dont start working until roughly 450 degrees, so they have an in built heater circuit to speed this process up. Its normally this which packs up - which means you need a new oxygen sensor.

 

sounds like a bad 02 sensor

 

Thanks very much fellas .

 

That sensor is referred to as the A/F sensor and lives in the manifold just before the up pipe.

Make sure you get the right one...........

22641AA042

 

100% O2 probe. I had the same code not so long ago.

 

The I/M ( inspection/maintainence ) readout means that the ECU has not yet run the checks on the catalyst and the oxygen sensor performance. These msgs are likely to show because you cleared the fault codes and the process of checking these components ( called component monitor ) does not happen until certain driving conditions are met.

After a mixed drive these should come up OK, however the P0031 might inhibit the Cat and O2 tests.

 

Cheers fella, most helpfull
The I/M messages read as that before I cleared the codes.

 

That just means the checking process has not run, it needs quite a specific drive cycle and may never change. Ideally the checks should run every time the vehicle is driven but as the data is never checked ( such at at MOT etc. ) it doesnt really matter.

 

just had this myself.
Its defo front lambda sensor not working.
I recommend world car parts for an oe replacement at a fraction of dealer prices.

 

Same as above,defo go for the denso ones mate at worldcarparts.

 

Cheers chaps, bit better than the 190+vat my local factor wants for an adl one!

What are they like to fit, is the wiring a mare to route or is it fairly straight forward?

 

I can only talk about blobeye but
I got mine for just under £100 delivered from worldcarparts. It was a denso one exactly the same as the one they put on at the factory. The wiring had push clips in the right places to tidy it onto a bracket. Very easy.
Hardest part about fitting is getting the old sensor out but if you have an offset lambda socket its a lot easier and it can all be done through the inspection panel in the drivers wheel arch.
Wiring is very simple as its just straight up and plugs in by the boost solenoid.

 

One of these will make life a lot easier for this job:

 

Same for an Impreza...........

http://www.scoobymods.com/showthread...nsor-9398.html

 

Thanks, it is a blob that I have got.
Been on the site they are £86.40, how much do they charge for delivery?
Doesn't sound too difficult then, cheers.

 

This is the one for a blob wrx that i bought:
http://www.worldcarparts.co.uk/Defau...oogle_shopping
£87.60 + £6.65 UPS next day delivery